In general, slide fasteners are roughly classified into two representative types which are a slide fastener of a normal type in which coupled right and left element rows are exposed as being disposed at a tape top face side of fastener tapes and a slide fastener of a concealed type (i.e., a so-called concealed slide fastener) capable of concealing coupled right and left element rows not to be viewable from the outside. Such a concealed slide fastener is preferably used for products such as various clothing and shoes, and recently, has been used for products such as seat covers for seats of automobiles or trains as taking advantage not to worsen product design owing to the concealing characteristics.
An example of such a concealed slide fastener is disclosed in Japanese Utility Model Application Publication No. 51-4826 (Patent Document 1).
A concealed slide fastener 80 disclosed in Patent Document 1 includes a right-and-left pair of fastener stringers 81 and a slider 82 capable of opening and closing the right and left fastener stringers 81, as illustrated in FIG. 13.
Each fastener stringer 81 of the right and left includes a woven fastener tape 83 and a continuously-shaped fastener element 84 which is sewn to the fastener tape 83. Each fastener tape 83 includes a tape body portion 83a, a tape bend portion 83b bent into a U-shape as extending from one side edge of the tape body portion 83a in the tape width direction, and an element mounting portion 83c to which a fastener element is sewn as further extending from the tape bend portion 83b. Further, a hardened portion 83d hardened by being impregnated with synthetic resin liquid is disposed to the element mounting portion 83c and a part of the tape bend portion 83b at the element mounting portion 83c side.
The fastener element 84 includes a coupling head 84a, upper and lower leg portions 84b, 84c extending from the coupling head 84a, and a connecting portion 84d which connects the mutually adjacent fastener elements 84. Further, a recess 84e to which the fastener tape 83 is inserted is formed at the upper face of the upper leg portion 84b which is contacted to the fastener tape 83.
In the concealed slide fastener 80 of Patent Document 1, the fastener element 84 is sewn to the hardened element mounting portion 83c of the fastener tape 83 with a sewing thread 85 in a state that the hardened portion 83d of the fastener tape 83 is fitted to the recess 84e which is formed at the fastener element 84.
According to the concealed slide fastener 80 of Patent Document 1, since the element mounting portion 83c and a part of the tape bend portion 83b of the fastener tape 83 are hardened, a closely-contacted state between the tape bend portions 83b of the right and left fastener tapes 83 can be stably maintained when the right and left fastener elements 84 are coupled.
Accordingly, even if lateral tension force to laterally open the fastener tapes 83 is applied in a state that the right and left fastener elements 84 are coupled, for example, clearance-forming between the right and left tape bend portions 83b can be prevented by preventing the tape bend portions 83b which are closely contacted to each other from moving in a separating direction. Thus, the right and left fastener elements 84 in a coupled state can be stably concealed not to be viewable from an exposure face side of the concealed slide fastener 80.
Further, in Patent Document 1, a concealed slide fastener in which hardening is performed by fixing a synthetic-resin-made film body to one face (i.e., a tape outer face) of a partial area of a fastener tape instead of hardening a partial area by impregnating with synthetic resin liquid is disclosed as a modified example of the concealed slide fastener. It is possible to harden a partial area of a fastener tape also by fixing a synthetic-resin-made film body to the partial area of the fastener tape as described above. Thus, a closely-contacted state between the tape bend portions of the right and left fastener tapes can be stably maintained also by fixing the film body in a state that the right and left fastener elements are coupled. In this manner, the fastener elements can be stably concealed.